Aspects of arbuscular mycorrhizal fungi in an atlantic forest chronosequence parque estadual turístico do Alto Ribeira (petar), SP

Abstract

Mycorrhizal colonization was assessed in roots of trees within an Atlantic Forest chronosequence, located in the southeastern of São Paulo State, Brazil, inside Tourist State Park of the High Ribeira Valley (PETAR). The phytosociological survey was carried out in three adjacent areas, all on calcareous soil, which correspond to different time intervals during which they have been left abandoned following a slash-and-burn agricultural perturbation. Early Phase (EP) with 15 years; Mid Phase (MP) with 25 years; and Late Phase (LP) with more than 36 years without clear-cut. The inventory indicated a continuum of tree species substitution, which is dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. (Mimosoideae) in the earlier successional phases. Mycorrhizal colonization, estimated by the occurrence of the mycorrhizal structures in the tree species roots, diminished during the season with less rain (winter), and showed no significant differences between successional phases in the wet season (summer). Rather, the mycorrhizal colonization was correlated with occurrence of the tree’s successional status: being positively correlated with occurrence of pioneer species, and negatively correlated with late secondary species. Mycorrhizal colonization was also correlated negatively with soil organic matter and base saturation. Twenty five species of arbuscular mycorrhizal fungi belonging to four genera were identified. Six species were only identified to generic level. The species Glomus etunicatum Becker & Gerd. represented 10% of the total number of spores and occurred in all phases and seasons, while the genus Glomus represented 57% of the total of spores found in the rhizosphere. The diversity indices evaluated for the mycohrriza community were: H’ = 2.3, J’ = 0.97 and R = 4.12. These results are a contribution to the knowledge of The Atlantic Forest biodiversity and may have implications to support programs regarding rehabilitation of degraded vegetation in one of the World’s most threatened Biomes.

Occurrence of arbuscular mycorrhizal fungi in soils of early stages of a secondary succession of Atlantic Forest in South Brazil

“…Our study along a successional gradient corroborates those of Aidar et al (2004) who detected 13 species of Acaulospora and 11 species of Glomus in a chronosequence within an area of Atlantic Rain Forest. We speculate that predominance of the Acaulosporaceae in our study could be the result of either contemporary ecological (e.g., soil chemical characteristics, plant species) or historical factors (e.g., dispersal, local extinction).…”

“…In the Southeastern region, Aidar et al (2004) found 29 taxa of AMF in a chronosequence of Atlantic Forest successional stages; however, they discussed differences in fungal species richness regarding wet and dry season and comparison with other studies rather than wiht plant successional stages. Our results may contribute to the knowledge of fungus species distribution in tropical regions, where fungi associated with vascular plants are scantly studied and poorly known (Hawksworth 1991).…”

Caracterización basada en morfotipos de las comunidades de hongos micorrízicos arbusculares en un bosque seco tropical restaurado, Isla de Margarita-Venezuela

“…C. etunicatum and R. intraradices were found in all treatments, which is consistent with the report by Oehl et al (2010) who considered these ubiquitous species as "generalists", strongly associated with highly disturbed sites. In another ecosystem type (the Brazilian Atlantic Forest), Aidar, Carrenho and Joly (2004) found that C. etunicatum occurred in all successional phases and seasons in field samples. On the other hand, two AMF species were collected exclusively in the non-restored plots (D. spurca and F. geosporum).…”

Ocorrência de fungos micorrízicos em catuaba (Anemopaegma arvense (Vell.) Stell. ex de Souza - Bignoniaceae), uma planta medicinal do Cerrado em risco de extinção

“…Os FMAs são frequentemente encontrados em associação com espécies nativas em ecossistemas naturais e a ocorrência nestes locais favorece o estabelecimento, a sobrevivência e o crescimento de plantas hospedeiras e não hospedeiras devido ao aumento na absorção de água e nutrientes, especialmente fósforo, nitrogênio, zinco e cobre (Pouyú-Rojas & Siqueira, 2000;Aidar et al, 2004, Jamarillo, 2011, Camargo-Ricalde et al, 2012. As MAs também estão envolvidas…”

“…Contudo, a formação, a ocorrência e a eficiência das MAs podem ser diretamente afetadas por alguns fatores inerentes à planta, ao solo, ao ambiente e seu manejo, resultando que o grau de benefício com a simbiose pode variar entre e dentro das espécies, (Siqueira, 1988;Grazziotti, 1999;Miranda & Miranda, 2001;Moreira & Siqueira, 2002;Aidar et al, 2004). A simbiose torna-se mais importante quanto maiores forem as dificuldades ou o nível de estresse impostos pelo ambiente, tais como as condições nutricionais subótimas (Siqueira & Saggin-Júnior, 1995;Smith & Read, 1997;Guzmán-González & Farías-Larios 2005).…”